Cutting instruments such as scissors and punches, and certain forceps have precisely aligned jaws which pivot to each other to provide the desired function, which if misaligned, severely reduces the performance of the tool, and if severe enough, causes damage if not complete destruction of the tool. Frequently, such pivoted cutting or clamping elements are mounted at the end of an operating rod or shaft, distal from the operator handle. Typically, when the working surfaces are experiencing difficulty, the operator twists the instrument by applying additional force to the cutting or clamping jaws via the handle, and also applies a torsion along the axis of the handle which is applied to the cutting or clamping jaws via the pivot point of the jaws. Moreover, when the jaws become misaligned through normal use, such misalignment often results in the instrument self-destructing.
The primary response of instrumentation manufacturers to minimize the problem of tip misalignment is to increase the relative size of the pivot points, which results in only a limited improvement in maintaining jaw tip alignment as the instrument is rotated or otherwise abused by the operator.
Moreover, cutting instruments such as scissors and punches typically have a continuous cutting surface to engage the tissue. The continuous cutting surface must be precisely aligned to provide optimal cutting, and further increases the necessity of the aforementioned tip alignment to provide optimal, if not useful instrument operation.
Furthermore, the amount of tissue which is excised by the cutting tool, or grasped by the jaws is largely determined by the effectiveness of the tip or most distal end of the cutting surfaces to engage the tissue, which is typically continuous with the adjacent perimeter portions of the jaw. However, the effectiveness of the continuous tip to engage the tissue is severely limited, and is further reduced as the tip becomes dull through use or misalignment.